When modelling a large and complex system, clarzty of the speczfication becomes an znaportant factor. I n object-oriented specification, the states of individual objects are captu...
Following results are sketched in this extended abstract: (1) Datalog recursive programs where each rule has at most one subgoal called unit recursions are shown to be bounded, wit...
We investigate and compare two forms of recursion on sets for querying nested collections. The rst one is called sri and it corresponds to sequential processing of data. The second...
Partial information in databases can arise when information from several databases is combined. Even if each database is complete for some \world", the combined databases wil...